i dont find the function to upload a QV document, so I attached some screenshots.
Its not the perfect way, but it will group the revenues of companies.
I used "Company" as list of company names and "Revenue" as the revenue of the company.
At the moment I dont have any access to my final document - just built you a fast example.
It will group the the Top 10, Top 20 and Top 30 companies and other companies as others.
Hope it helps.
Please define the dimension as =if(AGGR(CLASS(RANK(SUM([Revenue]))-1,10,SUM([Revenue])),[Company])<=20,AGGR(CLASS(RANK(SUM([Revenue]))-1,10,SUM([Revenue])),Company))
It will look like this:
The final result will look like this: